• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4B
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• pp.435-441
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• 2009

The one-time password system solves the problem concerning password reuse caused by the repeated utilization of an identical password. The password reuse problem occurs due to the cyclic repetition at the time of password creation, and authentication failure can occur due to time deviation or non-synchronization of the number of authentication. In this study, the password is created asynchronously and exchanged with the user, who then signs using a digital signature in exchange for the password and a valid verification is requested along with the certificate to ensure non-repudiation. Besides this, a verification system for one-time password is proposed and designed to improve security by utilizing the validity verification that is divided into certificate verification and password verification. Comparative analysis shows that the mechanism proposed in this study is better than the existing methods in terms of replay attack, non-repudiation and synchronization failure.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.2
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• pp.127-133
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• 2008

We assessed the coastal landscape of Jeju and Busan cities, respectively. In the study, we tried to estimate the coastal landscape based on the micro-scale and visualization landscape concepts. According to the estimation, the seawater pumping line causes the serious problem of coastal landscape. It means that water management treatment system of coastal region has been an important problem in Jeju city and Busan city since the slight problem was not corrected such as the distributions of pipeline of the pumping system making a bad view in coastal region. To solve the problem, we observed the pipeline distributions that were on the surface around the coastal region. we proposed two methods, that is, one is a short time treatment, the other is a long time one. The short is based on the colour treatment, which is pipeline colour changing into surround natural one. The long time is the construction design method which needs construction management method. Although the later method was very useful in Jeju island and Busan city. However, it takes a lot of time and money. Therefore, in the situation, the short time plan is more useful method than the long time one.

• Proceedings of KOSOMES biannual meeting
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• 2008.05a
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• pp.177-180
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• 2008

Based on Latti(1974) and Jacobs&Way(1968)'s theory, we estimate the coastal area of Jeju and Busan cities. According to the estimateio, The seawater pumping line causes the problem of coastal landscape. Water management treatment of coastal region has been an important problem in Jeju city and Busan city since the distributions of pipeline if the pumping system made a bad view in coastal region. To solve the problem, we observed the pipelines that are on the surface around the coastal region we proposed two methods, that is, one is a short time treatment, the other is a long time one. The short is based on the colour treatment, which is pipeline colour changing into surround natural one. The long time is the construction plan design method. Although the later method was very useful in Jeju island. However, it takes a lot of time and money. Therefore, in the situation, the short time is the better than the long time one.

• Industrial Engineering and Management Systems
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• v.4 no.2
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• pp.192-197
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• 2005

Among many amplitude parameters, Kurtosis (4-th normalized moment of probability density function) is recognized to be the sensitive good parameter for machine diagnosis. Kurtosis has a value of 3.0 under normal condition and the value generally goes up as the deterioration proceeds. In this paper, simplified calculation method of kurtosis is introduced for the analysis of impact vibration with one sided affiliated impact vibration which occurs towards the progress of time. That phenomenon is often watched in the failure of such as bearings’ outer race. One sided affiliated impact vibration is approximated by one sided triangle towards the progress of time and simplified calculation method is introduced. Varying the shape of one sided triangle, various models are examined and it is proved that new index is a sensitive good index for machine failure diagnosis. Utilizing this method, the behavior of kurtosis is forecasted and analyzed while watching machine condition and correct diagnosis is executed.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.22 no.2
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• pp.201-209
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• 2009

Objective : The purpose of this study is to know the satisfaction of Miso Facial Acupuncture on thirty-one case. Method : Thirty-one patients(more than third treatment) answer the question, It include age, sex, purpose, the number of treatment time, degree of satisfaction, so on. And I study satisfaction of ages, treatment time, treatment purpose. Results and conclusion : Among the thirty-one patients, 83.37% satisfacted the treatment result. and They will admonish the other peaple to treat Miso Facial Acupuncture. Miso Facial Acupuncture is includuced of one of as an effective therapy to the for skin disease such as freckles, acness, facial palsy and facial dissymmetry.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.457-461
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• 1988

In this study an one-board micom controlled precision temperature control system has been developed. The digital temperature control system is consisted of an one-board micom as digital controller, a 12-bit A/D and D/A converter, a power amplifier, a NTC thermister, a preamplfier and a heat chamber. An operating control program for the control system was written in Z80 machine language. A Dual-PID predictor control algorithm was proposed. Experments were conducted with different sampling time and limitted error value. As a result, the temperature in a heat chamber can be well controlled within +- 0.2 .deg.C when the sampling time was applied to 10 sec and the limitted error value +- 0.5 .deg.C under the dual-PID predictor control algorithm. By means of one-board micom overall system has been reduced in size and volume, thus the system becomes compact and less expensive.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.6
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• pp.488-496
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• 2019

The estimation of block erection work time at a dock is one of the important factors when establishing or managing the total shipbuilding schedule. In order to predict the work time, it is a natural approach that the existing block erection data would be used to solve the problem. Generally the work time per unit is the product of coefficient value, quantity, and product value. Previously, the work time per unit is determined statistically by unit load data. However, we estimate the work time per unit through work time coefficient value from series ships using machine learning. In machine learning, the outcome depends mainly on how the training data is organized. Therefore, in this study, we use 'Feature Engineering' to determine which one should be used as features, and to check their influence on the result. In order to get the coefficient value of each block, we try to solve this problem through the Ensemble learning methods which is actively used nowadays. Among the many techniques of Ensemble learning, the final model is constructed by Stacking Ensemble techniques, consisting of the existing Ensemble models (Decision Tree, Random Forest, Gradient Boost, Square Loss Gradient Boost, XG Boost), and the accuracy is maximized by selecting three candidates among all models. Finally, the results of this study are verified by the predicted total work time for one ship among the same series.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.6
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• pp.381-386
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• 2002

A field experiment was conducted to evaluate the effect of split-application of slow-release fertilizer on the tea plant. The yield of the 1st harvested tea leaves had increased 12% in the slow-release fertilizer(two time split manuring) compared with the traditional manuring(four time split manuring), but that of the slow-release fertilizer to one time split manuring had decreased $6{\pm}3%$. In case of the 1st harvested leave, the contents of chemical components related to quality such as total nitrogen, total amino acid, chlorophyll, vitamin C and theanine were somewhat higher in the leaves of slow-release fertilizer(two time split manuring) treatment than in the traditional manuring, but that of tannin was low. The one time split manuring of slow-release fertilizer had a contrary tendency with two time split manuring treatment. In scoring test, appearance and quality of green tea were more excellent in the two time split manuring compared with one time split manuring of slow-release fertilizer and with the traditional manuring (four time split manuring). Therefore, use of slow-release fertilizer increased yield and quality of tea leaves, and decreased loss of nitrogen, phosphate and potassium.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.2
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• pp.35-40
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• 2024

In this paper, we validate the practicality of the OnePIC app implemented in the previous study by analyzing the execution and storage performance. The OnePIC app is a camera app that allows you to get a photo with a desired focus after taking photos focused on various places. To evaluate performance, we analyzed distance focus shooting time and object focus shooting time in detail. The performance evaluation was measured on actual smartphone. Distance focus shooting time for 5 photos was around 0.84 seconds, the object detection time was around 0.19 seconds regardless of the number of objects and object focus shooting time for 5 photos was around 4.84 seconds. When we compared the size of a single All-in-JPEG file that stores multi-focus photos to the size of the JPEG files stored individually, there was no significant benefit in storage space because the All-in-JPEG file size was subtly reduced. However, All-in-JPEG has the great advantage of managing multi-focus photos. Finally, we conclude that the OnePIC app is practical in terms of shooting time, photo storage size, and management.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.97-100
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• 1997

Fieldbuses are used as the lowest level communication network for real-time communication in factory automation and process control systems. Data generated from field devices can be divided into three categories: sporadic real-time, periodic real-time and non real-time data. Since these data share one fieldbus network medium, it needs a method that allocate the limited bandwidth of fieldbus network to the sporadic real-time, periodic real-time and non real-time traffic. This paper introduces an implementation method of bandwidth allocation scheme introduced in [51 on PROFIBUS. Using the modified PROFIBUS FDL(Fieldbus Data Link layer), the bandwidth allocation scheme introduced in [51 is verified by the experiments.